This invention relates to control valves and, more particularly, to control valves for providing fluid flow to and from a torque converter and clutch assembly.
In current transmissions employing torque converters, most of these mechanisms employ what is termed a torque converter clutch. The torque converter clutch is a selectively engageable mechanism that places the torque converter in a 1:1 drive condition thereby improving the overall efficiency of the transmission.
The torque converter is a hydrodynamic assembly, which requires fluid for the proper operation thereof. When a clutch is added to the torque converter, such that a torque converter and clutch assembly is attained, the fluid pressure to the torque converter must also apply and release the torque converter clutch.
In present transmissions, the fluid fed to the torque converter and clutch assembly is controlled by a torque converter regulator valve and a torque converter control valve. The torque converter regulator valve controls the level of pressure needed to apply the torque converter clutch and the torque converter control valve determines the direction of flow through the torque converter. In other words, the torque converter regulator apply clutch is a downstream regulator valve and the torque converter control valve is a directional valve.
With the use of two valves, it is required that the transmission have two valve spools, two separate valve bores and fluid transfer channel which interconnect these two valve spools.
It is an object of the present invention to provide a torque converter clutch control mechanism having a single valve spool element.
In one aspect of the present invention, the torque converter clutch control mechanism supplies fluid pressure from a conventional transmission regulator valve to one area of a torque converter and clutch assembly and returns fluid from the torque converter and clutch assembly to a fluid cooler.
In another aspect of the present invention, the valve spool of the torque converter clutch control mechanism is directed to a second position wherein a regulated pressure is emitted from the torque converter clutch and control mechanism and supplies fluid pressure to another area of the torque converter assembly.
In a further aspect of the present invention, in a release condition, the torque converter clutch control mechanism supplies fluid pressure to a release side of the torque converter and clutch assembly and return fluid is directed from an apply side of the torque converter and clutch assembly to a transmission cooler.
In a still further aspect of the present invention, in an apply condition, the torque converter clutch control mechanism supplies a regulated pressure to the apply side of the torque converter and clutch assembly and return fluid is directed from the release side of torque converter and clutch assembly to a fluid reservoir.
In yet still another aspect of the present invention, the torque converter clutch control mechanism includes a force motor control member which determines the apply and release positions of the spool valve of the torque converter clutch control mechanism and also supplies a bias pressure for the regulation of fluid pressure to the torque converter during the apply condition.